Draft gear



July 1. 1924.

C. W. SHERMAN'ET AL DRAFT GEAR Filed July 8, 1921 3 Sheets-Sheet. l

July 1 W. SHERMAN ET L DRAFT GEAR 3 Sheets-Sheet. 2

Filed y 1921 I4 .59? yew-Z 215 a. "a h ,a'

HHHHUHF Patented July 1, 1924.

UNITED STATES CLIFTON W. SHERMAN AND EDWARD G. MCDOWELL, 0F HAMILTON, ONTARIO, CANADA; SAID MCDOWELL ASSIGNOB To SAID SHERMAN.

' DRAFT GEAR.

Application filed July 8,

To all whom it may concern:

Be it known that we, CLIFTON VQSHER- MAN, a citizen of Canada, and EDWARD C. MCDOWELL, a citizen of the United States,

residing at Hamilton, in the county of Nentworth and Dominion of Canada, and Province of Ontario, have invented new and useful Improvements in Draft Gears, of which the following is a specification.

This invention relates to that type of draft gears for railway cars which are interposed between the under or main frame of the car and the coupler and in which both frictional and spring resistance is utilized to absorb the buffing or pushing shocks due to the impact of one car on another when coupling cars and to enable the momentum of one car to be imparted more gradually to another car and absorb the pulling or jerking shocks when starting todraw the coupled cars, the former shocks being much more severe than the latter.

Due to a partial standardization of the construction of railway cars having as its object principally to facilitate repairs, there are certain limitations within which any design of a draft gear must be confined in order to permit its general use and interchange with other makes of draft gears. The standard adopted by the American Railway Association provides for the Type D automatic coupler which is attached to the draft gear by a key, and the general practice adopted by most roads provides that the underframe of the car shall have its draft sills spaced 12% and rear draft lugs on these sills spaced apart 243- to receive the draft gear, this being specially applicable to freight cars, thereby limiting thesize or capacity and the range or stroke of the draft gear.

The most prevalent, and so far, most successful type of draft gear, is that composed of relatively movable parts between which .are interposed various forms of members having co-operat-ing friction surfaces which act in conjunction with springs to retard or resist the coming together of the movable "I parts of the draft gear, the frictional resistance, due to the compression of the spring, being increased as the main movable parts of the gear approach each other. In general, the effectiveness of a draft gear depends upon the force required to compress the draft gear into a solid condition and also apart and the front 1921. Serial No. 483,335.

the distance which the gear moves in effectmg its full stroke and becoming solid, which force in turn depends on the frictional resistance and the strength of the spring, the capacity of the gear being increasedin pro-- portion to the increase in the force required to compress the gear or the length of the stroke to effect'such compression.

It is the general object'of this invention to provide an improved draft gear of this character which will come within the prescribed requirements of the A. R. A.; which has a small spring but a large friction'area; which has a long stroke and a large capacity; which is of simple construction and does not require a separate yoke to attach it to the coupler; and in which the spring pressure may be readily adjusted and a full bearing of the friction surfaces is obtained so that unequal wear on the same is eliminated.

A further object of this invention is to so construct and assemble the several parts that there is a clearance between certain of the elements which permits of automatically taking up wear in the draft gear and avoiding cutting down the efliciency of the gear.

In the accompanying drawings:

Figure 1 is a top plan view, partly in sec tion of onefonm of our improved draft gearsin connection with a car coupler and the underframe of a railwaycar. Figure 2 is a vertical longitudinal section of the same, showing the parts in full release position. Figures 3 and 4: are views similar to Fig. 2, but showing the parts in the buffing and pulling positions, respectively. Figures-5, 6 and 7 are transverse sections taken on'the correspondingly numbered lines in Fig. Figure 8 is a top plan view of modified form of our invention. Figures 9 and 10 are vertical. longitudinal sections of the gear shown in Fig. 8, with the parts in full releaseand in buffing positions, respectively. Figure 11 is a rear elevation of the 'gear' shown in Fig. 8. Figure12 is a cross section taken on line 12'12, Fig. 9. Figure 13 is a fragmentary longitudinal section showing another modification of our improvement. Figure 1a is a cross section on line 14:14, Fig. 13. I k 7 Similar characters of referenceindicate corresponding parts throughout the several views.

Referring to Figs. 17, represents the longitudinal draft sills of the main or underframe of the railway car which are preferably constructed of steel and are spaced apart cross-wise of the car a distance of twelve and seven-eighths inches and provided on their opposing inner sides with front draft lugs or stops 21 and rear draft lugs or stops 22, said front and rear draft lugs being spaced apart twenty-four and five-eighths inches in accordance with the requirements of the A. R. A.

23 represents the car coupler which may be of any approved form and construction and which has its butt or shank 24 arranged between the front draft lugs and connected with the underframe, so as to be capable of longitudinal movement relative thereto, this being preferably accomplished in the usual and well known manner by a draft key 90 passing transversely through an openlng in the coupler shank and through longitudinal slots 25 in the draft sills and confined against displacement by a head 26 arranged on the key outside of one sill, and a pin 27 arranged on the other end of the key outside of the other sill.

Arranged lengthwise between the sills is a draft yoke which may be variously constructed but which in the form shown in Figs. 17 comprises upper and lower V- shaped bars 28, 29, two forwardly-projecting coupling cheeks 30, 30 arranged on transversely-opposite sides of the front part of the yoke and provided with longitudinal slots 31 which receive the draft key but have a length greater than the width of the latter, and a rear or back follower 32 adapted in its rearmost position to engage the rear draft lugs on the sills. The longitudinal bars, coupling cheeks and back follower are cast integrally of steel, thus simplifying the construction, reducing the cost of manufacture and rendering the gear more efficient and durable. In its center the back follower is provided with a longitudinal guide opening 33 and above and below said guide opening with inclined wedge faces 34, 34, which diverge forwardly, the latter being preferably formed on blocks or pieces 35 of better wearing metal which are removably seated in recesses 36 in the back follower and thus permit these inclined faces to be easily renewed when worn out.

Movable lengthwise in the guide opening of the back follower is a central longitudinal wedge block 37 of cast steel which has its rear part provided with longitudinal parallel guide surfaces 38 which engage the longitudinal parallel sides of the opening 33 while its front part tapers forwardly and is provided with upper and lower forwardly converging inclined wedge faces 39. 40, 40 represent two transversely movable side wedge blocks of cast iron each of which is of substantially triangular or prlsm form 111 cross section and provided with inner and outer rearwardly converging inclined faces 42, 41 which engage respectively with one of the inclined faces of the back follower, and one of the inclined faces of the rear wedge block and a vertical front face 43. 44 is a movable or floating abutment or follower of rolled steel having the form of a plate which is arranged transversely in the yoke and engages its rear side with the vertical front sides of the side wedges or blocks and is provided on its rear side with a groove or recess 441 in line with the front end of the central wedge block 37 so that the latter will not engage the floating abutment when the parts are in full release position, as shown in Fig. 2.

45, 46 represent the inner and outer springs of a shock absorbing or cushioning spring device which bears at its rear end against the front side of the floating abutment while the thrust of its front end is transmitted to the rear wedge block, preferably by a thrust rod '47 extending lengthwise through corresponding openings 48, 49 in the floating abutment and the rear wedge block and provided at its front end with a head 50 which bears by means of an interposed washer 51 against the front end of the cushion spring device while its rear externally-threaded end is provided with an inner stop nut 52 bearing against the rear side of the rear wedge block and a lock nut 53 engaging the stop nut and being preferably of castle form to receive a cotter pin 54 which prevents the same from turning and becoming loose. The rear end of the thrust rod is preferably made square, as shown at 55, so that the same may be conveniently held by a wrench while the stop and lock nut are being turned on the thrust rod to secure the desired tension on the spring device.

56 represents a front follower of rolled steel which extends across the yoke and is guided in the horizontal slots formed therein between the upper and lower bars thereof and the front side of its opposite ends are adapted to bear against the front draft lugs but its rear side is spaced from the thrust head 50 of the thrust rod in the full release position of the gear. The outer coil 46 is assembled under an initial compression of about one-eighth of an inch and the inner coil is assembled under an initial compression of about one-half an inch and in the release position of the gear the head of the thrust rod is about three-eighths of an inch from the front follower 56. 57 represents a spring barrel and thrust casing of cast steel which encloses the cushion spring device and the front part of the thrust rod and which bears at its front end against the rear side of the front follower while its rear end bears against the front side of the float- -way practice.

wedges are permltted to move 1nwardly so ing abutment and the side wedge blocks and is provided with notches 80 which receive said floating abutment.

Assuming that the gear is in full release position, as shown in Figs. 1 and 2,the front follower 56 engages the front draft lugs 21 and the cheeks of the yoke, the back follower 32 engages the rear draft lugs 22, the rear wedge block 37 and floating abutment 44 are in flieir foremost position, the side wedge blocks are separated the maximum extent and the cushioning spring device 45, 46, is expanded to the limit permitted by the particular adjustment.

When the coupler receives a bufling from another car it is pushed backwardly against the front follower, causing the latter) to travel backwardly and to carry the spring barrel and floating abutment with it in the same direction, inasmuch as these parts abut successively against one another. floating abutment moves backwardly the side wedges are moved in the same direc tion but during this movement the side wedges are also forced inwardly toward the axis of the gear by the wedge action of'the inclined outer faces of the side wedge blocks against the wedge faces of the'back follower. This inward movement of the side wedge blocks toward each other and the wedging effect of theirincline d'inner sides against the inclined surfaces of the rear wedge block, as well as therearward thrust of the side wedge blocks against the rear wedge block, causes the latter to be squeezed rearwardly from between the side wedge blocks and moved lengthwise to a greater extent than the side wedge blocks and the f floating-abutment, spring barrel and front follower. This rearward movement of these parts and the inward movement of the side wedges continues until the floating abutment engages its rear side with the front side of the back follower, as shown in Fig. 3, at which time the shock absorbing capacity of the gear has been exhausted and has become what is generally called-solid in rail- In extreme cases the side that they nearly touch each other, this being possible by providing the opposing inner edges of the side wedges with notches 58 which enables the same to straddle the thrust rod, as shown in Fig. 3. This gear is preferably so designed that the front follower, floating abutment, spring barrel,

spring and side wedges move lengthwise three inches, while the rear wedgeblock by reason of its being squeezed away from the side wedge blocks and the floating 'abut-' ment travels an additional three inches,-

making the total longitudinal travel ofthe rear wedge block six inches.

As the s It therefore follows that in this gear the shock absorbing spring is carried bodily lengthwise of the gear during a full stroke a distance of three time the front follower, spring barrel and floating abutment are held stationary by the front draft lugs while the yoke having the back follower is drawn forwardly by the coupler, as shown in Fig. 4. In the operation of the gear when bufling and pulling, the compression of the spring causes" the rear wedge block to be pulled forwardly against the side wedge blocks, this pressure increasing in the same measure as the forward movement of the rear wedge block andethe inward movement of the side wedge" blocks progresses, thereby causing the lat ter to react on the rean wedge block and the back follower and increasing the fric- "tional contact between the three surfaces of each side wedge'block and'the three members against which the same reacts. This friction increases until the spring is compressed three inches, or almost solid. when the spring barrel comes in contact with the back follower andjthe gear becomes solid" so that furtherpushing or pulling of the coupler is transmitted directly to the underframe of the car.

It will be'noted that in this gear the wedges and spring do not react against any part directly connected with the car, but

instead the side wedge blocks react against the rear end of the spring and the rear. wedge block reacts against the front end of the spring, thereby causing the thrust rod,

rear wedge block and spring to float and move independently of the yoke and other parts engaging directly with the car. It is this feature which permits of obtaining a maximum travel of three inches in "the gear andstill confine all parts of the gear between the sills and draft lugs in accordance with the requirements of the A. R. A., and employ onlyone set of wedges and one spring. Furthermore, by placing the wedges one above the other andmoving the same ver-" tically, it is possible to use one set of wedges which'is from 25% to larger than if the same were placed crosswise of the sills,

thereby increasing the area so as to "reduce the pressure per unit area and decreasing the wear per umt area whereby the efficiency of the shock absorber is increased.

As this spring consistsof two sections, it is preferable to provide the washer of the thrust rod head with a rearward projection 91 of say three eighths of an inch, which bears only against the front end of the inner spring section and thus retains this section always under compression, thereby causing the system of wedges to be always held snug against each other and preventing lost motion, particularly when the gear is fully released.

By providing original clearance space in the release position of the gear between the rear or central wedge 37 and the floating abutment and between the front follower and the head 50 of the thrust rod, any wear be tween the side wedge blocks and the rear follower, floating abutment and rear wedge block will be automatically taken up by reason of the ability of the spring to expand for this purpose, thus leaving the gear constantly in such shape to operate most efficiently within the limits of its capacity to take up lost motion in the gear due to wear.

The ear shown in Figs. 17 may be assemblecI in various ways, for instance, by first engaging the side wedge blocks with the rear wedge block, and back follower, then inserting the spring barrel into the yoke through one of its side slots 81 and enga ing the rear end of same with the. front side of the side wedge blocks, then inserting the floating abutment from the top of the yoke into the notches 80 in the rear end of the spring barrel, so that the same is located between the barrel and side wedge blocks, then inserting the spring into the barrel from the front end of the latter and the yoke, then passing the thrust rod from the front end of the yoke rearwardly through the spring, spring barrel, floating abutment and rear wedge block and securing the same to the latter, and then passing the front follower transversely through the yoke fro-m one side thereof and engaging the same with the front end of the spring barrel, thereby looking all of the parts together in an assembled condition, ready to be mounted in the underframe of a car and to be connected with a coupler.

In the modified construction of the gear embodying, our improvements shown in Figs. 8 to 12, the rear wedge block and side wedge blocks are provided with openings 60, 61 and the corners of the back follower are notched, as shown at 62, for rendering these parts lighter without reducing their strength or efliciency. If desired, the washer may be omitted from the thrust rod in which case the head 63 on the front end of this rod may bear directly against the front end of the spring device, as shown in Figs. 9 and 10. The last-mentioned construction also shows the floating abutment 64 made in one piece with the spring barrel 65 instead of being made separate. For the purpose of more eifectively guiding the rear wedge-block on the back follower, the latter is provided on its rear side above and below the guide opening therein with rearwardly projecting guide lips 66, 66, which engage with the upper and lower sides of the rear wedge block and retain the same against vertical displacement during its longitudinal movement. In order to increase the length of contact between the several inclined or wedge surfaces, each wearing member 67 on the back follower 68 may be lengthened, as shown in Figs. 9 and 10, so that there will be practically a full contact between the same and the side wedges" in all positions of the latter regardless of whether the gear is fully released or under slight compression, thus obviating the possibility of wearing shoulders on the overlapping parts of the wedges. In this case the wearing blocks are detachably secured to the back follower by means of rivets 69. A similar increase in the extent of contact between the rear wedge block and the side wedge blocks is effected by enlarging the central opening 70 of the floating abutment and lengthening the rear wedge block so that its front end 71, in the released position of the gear, projects into the open ing 70, and thus provides a longer inclined surface on the rear wedge block for engagement with the side wedge blocks.

If desired, the yoke of the draft gear, as shown in Figs. 13 and 14c may have its upper and lower longitudinal bars 82 constructed in the form of channels in cross section and provided at their rear ends with inclined recesses 83 in whichare seated inclined blocks or plates 84: for engagement with the side wedge blocks, in which construction the internal parts of the gear are inserted through openings 85 in the side of the yoke.

In the several forms of our invention shown and described, the yoke or main frame of the gearserves as a means for attachment to the coupler, as a carrier for the internal parts of the gear, as a back follower to deliver the buff against the rear draft lugs, as a tension member to take the pull of the coupler, as a means for holding the outer friction blocks and transmit friction. pressure to the car, and also as a guide for the rear wedge block. By thus constructing a yoke having this capacity, the draft gear as a whole is materially simplified, and capa ble of being easily assembled as well as dis membered for inspection, adjustment and repairs.

Moreover, this draft gear is practically self-contained and can be applied to the car and coupler in an assembled condition.

An additional advantage in this draft gear consists in the "organization which produ'ces a rearward compression of the spring by a pull against the front end of the same from the rear of the gear which permits and tion bodily due to wear iii-the gear and per-,

mitting the spring to automatically take up this wear, the gear will always be maintained in a condition of maximum efficiency and ready to cushion the shock from the beginning to the ending of any bufiing or pull ing strains to which the same is subjected.

lVe claim as our invention:.

1. In a railway draft gear, a yoke adapted to engage a rear stop on thecar frame and adapted to beconnected with a coupler and having a rear follower provided with an inclined friction face, a front follower mounted on the yoke and adapted to engage a front stop on the car frame, a spring, a movable abutment which receives the thrust of said front follower and one end of said spring, a longitudinally movable block having an inclined friction face and connected with the other end of said spring, and a laterally movable block sliding transversely on said movable abutment and provided with oppositely inclined friction faces which engage with the corresponding faces of said longitudinally movable block and said rear follower.

:2. In a railway draft gear, a yoke adaptedto engage a rear stop on the car frame and adapted to be connected with a coupler and having a rear follower provided with an inclined friction face, a front follower mounted on the yoke and adapted to engage a front stop on the car. frame, a spring, a spring barrel enclosing said spring'and bearing at its front end against said front follower, a movable abutment which receives the thrust of the rear ends of said barrel and spring, a longitudinally movable block having an inclined friction face and connected with the other end of said spring, and a laterally movable block sliding transversely on said movable abutment and provided with oppositely inclined friction faces which engage with the "corresponding faces of said longitudinally movable block and said rear follower.

8. In a railway draft gear, a yoke adapted to be connected with a coupler and" having a rear follower and adapted to engage a rear stop on the car frame, a front follower mounted on the yoke and movable lengthwise thereon and adapted to engage a front stop on the car frame, a spring, a

spring barrel enclosing said spring and bear ing at its front end against said front follower, a movable abutment which receives the thrust of the rear end of said barrel and spring, a longitudinally movable block con nected with the front end of said spring, and a laterally movable block sliding transversely on said movable abutment and having a wedging engagement with said rear follower and longitudinally movable block.

l. In a railway draft gear, a yoke adapted to be connected with a coupler and having a rear follower and adapted to engage a rear stop on the car frame, a front follower mountedon the yoke and movable lengthwisethereon and adapted to engage a front stop on the car frame, a spring, a spring barrel enclosing said spring and bearing at its vfront end against said front follower, a movable abutment which receives the thrust of the rear end of-said barrel and spring,

a longitudinally movable block arranged in rear of saidmovable abutment, a longitudinal rod extending through said movable abutment and connected at its front end with the front end of said spring and'at its rear end with said longitudinally movable block, and a laterally movable block which slides transversely on said movable abutment and which has a wedging engagement with said longitudinally movable block and said rear follower.

5. In a railway draft gear, a yoke adapted to be connected with a coupler and having a rear follower and adapted to engage a rear stop on the car frame, a front follower mounted on the yoke and movable lengthwise thereon and adapted to engage a front stop on the car frame, a spring, a spring barrel enclosing said spring and bearing at its front end against said front follower, a movable abutment which receives the thrust of the rear end of said barrel and spring, a longitudinally movable block arranged in rear of said movable abutment, a longitudinal rod extending through said movable abutment, longitudinally movable block and spring and provided at its front end with a head which receives the thrust of the front end of said spring, and provided at its rear end with a screw nut bearing against the rear end of said longitudinally movable block, and a laterally movable block which slides transversely on said movable abutment and which has a wedging engagement with said longitudinally movable block and said rear follower.

6. In a draft gear, a yoke having a rear follower provided with an inclined wearing surface, a laterally movable wedge block engaging said wearing surface, a longitudinally movable wedge block engaging with said transversely movable block, a movable abutment engaging with said laterally movable block, a spring engaging said movable abutment, a spring barrel enclosing said spring and engaging said movable abutment and laterally movable block, a connection between said spring and longitudinally movable block, and a front follower engaging said barrel, said wearing surface being of such an extent that the same engages with practically the entire opposing surface of the laterally movable block When the draft gear is in a released condition.

7. In a draft gear, a yoke having a rear follower, a Wearing block detachably mounted on the yoke and having an inclined face, a laterally movable block having a Wedging engagement With said Wearing block, a lon gitudinally movable block having a Wedging engagement with said laterally movable block, a movable abutment engaging with said laterally movable block, a spring engaging With said movable abutment and connected With said longitudinally movable block, and a front follower adapted to exert rearward pressure against said laterally movable block.

8. In a draft gear, a yoke having a rear follower provided With a longitudinal guideopening and guide lips extending rearwardly therefrom adjacent to said opening, a longitudinally-movable Wedge block guided in said opening and on said lips, a laterally movable Wedge block having a Wedging engagement With said follower and longitudinally movable block, a spring adaptedto eXert pressure against said laterally movable block and connected With said longitudinally movable block, and a front follower adapted to exert pressure against said laterally movable block.

CLIFTON "W. SHERMAN. ED'WARD C. MCDOWVELL.

lVitnesses:

H. KRUEGER, N. T. ROBINSON. 

